Footwear often serves a functional role related to a particular activity. One of the most well-known examples of footwear function is protection of a wearer's feet from the external environment. In particular, people wear shoes to protect the bottoms of their feet from the surface over which they walk. Footwear may also provide added traction as a wearer walks, support for a wearer's foot, warmth, etc. Footwear often serves these and other functions in varying degrees. For example, a person may need a relatively rugged shoe when walking outside, but only need a light slipper when walking inside.
Because of the many functions that footwear serves, people often have multiple pairs of shoes designed for use in different circumstances. This is can be inconvenient. If a person expects to encounter various environments for which different shoe types may be appropriate, that person may be forced to carry one or more pairs of shoes in addition to the shoes he or she may presently be wearing.
As in many fields, manufacturing presents many challenges in the footwear arts. As indicated above, a shoe often needs a rugged surface in the outsole region so as to support the wearer's foot, to provide traction and/or for durability. However, it is frequently desirable that other parts of a shoe be softer and more compliant. Because of these different requirements, shoes are often fabricated from multiple types of materials. These diverse materials are usually joined in some manner, e.g., stitching, gluing, etc. Joining different component types often requires additional manufacturing steps. Reducing the number of joining operations reduces manufacturing steps, thereby reducing cost.
Disposal of worn-out shoes is another challenge in the footwear arts. At the end of a shoe's life cycle, joined components must often be separated. In particular, the different materials used to construct a shoe often have differing recycling requirements. Separating components that have been glued, stitched or otherwise bonded adds to the inconvenience and expense of recycling. When recycling is not convenient, some persons will simply dispose of shoes with non-recycled refuse. If a shoe could be more easily separated into components, people will be encouraged to recycle that shoe.